The poor fracture toughness limits the widespread application of high-strength cast Mg-Re-Zn alloys. Regulating the alloy microstructure, with phases such as α-Mg, blocky LPSO (long-period stacking order), and lamellar LPSO, offers various possibilities to enhance ductility by casting and heat treatment. This study categorizes different interface types concerning crack initiation, propagation, and ultimate fracture toughness. It distinctly presents the results of interface modulation related to alloy composition and heat treatment, elucidating the influence on crack initiation and propagation paths. Consequently, it proposes structural configurations rule and relevant heat treatment processes that can optimize and improve alloy fracture toughness. Blocky LPSO should have appropriate dispersion and size while avoiding lamellar LPSO.

High reactivity and ease of ignition are the major obstacles for the application of Mg alloys in aerospace. Thus, the ignition mechanisms of Mg alloys should be investigated systematically, which can guide the ignition-proof alloy design. This article concludes the factors influencing the ignition resistance of Mg alloys from oxide film and substrate microstructure, and also the mechanisms of alloying elements improving the ignition resistance. The low strength is another reason restricting the development of Mg alloys. Therefore, at the last section, Mg alloys with the combination of high strength and good ignition-proof performance are summarized, including Mg-Al-Ca based alloys, SEN (Mg-Al-Zn-Ca-Y) alloys as well as Mg-Y and Mg-Gd based alloys. Besides, the shortages and the future focus of theses alloys are also reviewed. The aim of this article is to promote the understanding of oxidation and ignition mechanisms of Mg alloys and to provide reference for the development of Mg alloys with high strength and excellent ignition-proof performance at the same time.